Quadruplex telegraphy



PATENTED' OCT. 18, 1904. J. c. BARCLAY. QUADRUPLEX TELBGRAPHY.

-' N0 MODEL.

APPLICATION FILED PERL 1904.

Patented October 18, 1904.

PATENT OFFICE.

JOHN G. BARCLAY, OF NEW YORK, N. Y.

QUADRUPLEX TELEGRAPHY.

SPECIFICATION forming part of Letters Patent No. 772,396, dated October 18, 1904.

Application filed February 1,,1904. Serial No. 191,498. (No model.) 7

To all whom, it may concern.-

Be it known that I, JOHN G. BARCLAY, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Quadruplcx Telegraphs; and I do hereby declare the following to be a full, clear, and exact description of the same, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to quadruplex telegraphs, and particularly to that class thereof wherein two messages in the same direction are transmitted by current pulses of ditferent polarity.

My invention consists. in novel means for connecting two generators of opposite polarity to the line alternately, in means for operating the vibrating connectors of a plurality of quadruplex lines from a common source, and generally in features of invention hereinafter set forth, and particularly pointed out in the claims.

The objects of my invention are to simplify and improve the working of quadruplex telegraphs, and particularly of that class of quadruplex telegraphs employing currents of different direction for transmitting different messages, to avoid sparking at the contacts of the devices employed for connecting the transmitters alternately to the line, to avoid the use of special instruments and permit the use of standard instruments of well-known type, to operate the connecting devices of a plurality of quadruplex lines from .a common source, and in general to make the apparatus employed less expensive and more reliable and certain in action.

I will now proceed to describe my invention, with reference to the accompanying drawing, showing diagrammatically the apparatus and circuits at a transmitting-station at which two quadruplex lines terminate, and will then point out the novel features in claims.

In the drawing two line-wires 1 1 are shown. The transmitting and receiving apparatus for these lines are identical, and therefore the said apparatus of only one of the lines need be described. For each line there are transmitters 2 and 3 of ordinary type, each controlled by an appropriate hand-key and local circuit. The particular transmitters indicated are of the walking-beam type, the back contact-stop being connected to ground and the front contact-stop 5 connected to one of the two transmitting-generators 6 and 7. The stops 5 of these transmitters are connected, respectively, to opposite terminals of their respective generators.

8 8 are vibrating connecting-relays for the two lines 1. They may be ordinary polar relays, one contact-stop of each relay connected to the armature of the corresponding transmitter 2 and the opposite contact-stop to the armature of the corresponding transmitter 3. The armature of each of these connecting-relays is connected to its corresponding line 1 .and artificial line 9, and these line and artificial line-circuits pass through differentiallywound magnet-coils of receiving-relays l0 and 11 in the ordinary manner. The receiving relays employed are arranged each to respond to currents of one polarity only-relay 10, for example, being arranged to respond only to positive current pulses and relay 11 only to negative current pulses. wound, these relays are not affected by outgoing current pulses of either polarity and are affected only byincoming current pulses from the opposite end of the line, at which will be transmitting and receiving instruments similar to those indicated in the diagram. The particular receiving-relay illustrated is of a well-known type, having its magnet-core magnetized by a permanent magnet 12, the eifect of the permanent magnet on the armature 13 being neutralized by an opposing electromagnet 14: in a local circuit. Relays 10 and 11 operate sounders' 15 and 16 through repeatingsounders 17 and 18.

The armatures of connecting-relays 8 are caused .to vibrate continuously and rapidly throughout the transmission of messages, so as to connect transmitters 2 and 3 alternately to the line. For vibrating these armatures I preferably construct said relays 8 as polar Being diiferentially relays and place them in a circuit 19, through which an alternating current flows. This current may be derived from an alternating-current dynamo 20, which preferably is a dynamomotorthat is to say, a combined motor and dynamo driven by current in a driving-circuit 21 and generating current for the circuit 19. Mot0r-dynamos such as are employed in telephone systems for ringing purposes are suitable for operating relays 8. The motor dynamo may be constructed. to be driven either by direct or alternating current; but it will be understood that the generator for circuit 19 may be driven in any other suitable manner, or that a fluctuating or alternating current may be produced in such circuit in any other suitable way, and that I may use instead of polar relays 8 other relays adapted to cause their armatures to vibrate when placed in a circuit in which a fluctuating or alternating current flows.

The operation of the system is as follows: The generator 20 being in full operation, the armatures of relays 8 vibrate continuously and rapidly between their contact-stops, each relay thereby connecting its transmitters 2 and 3 alternately to the line. WVith whichever stop the armature of relay 8 may be in contact the line is connected through the corresponding transmitter, 2 or 3, to ground, either directly or through one or the other of the two generators 6 and 7 The interval of motion of the armature of relay 8 from one stop to the other, during which motion the line is not connected toground, is too brief to interfere in any way with messages from the distantend. When the keys of both the transmitters 2 and 3 are open, the line is connected to ground directly. If the key of transmitter 2, for example, be depressed, transmitter 2 is operated and the circuit completed from generator 6 through transmitter 9. to one contact-stop of relay 8, so that when ever the armature of that relay is in contact with the stop generator 6 is placed to the line and a signal is transmitted through the line to the distant end. Outgoing signals do not affect the home receiving-relays 10 and 11, because of the differential winding of those relays, but affect only the corresponding relays at the distant end.

It will be obvious that connecting-relays 8 for a number of quadruplex lines may be included in one circuit 19, one generator 20 or other means for producing fluctuating current in circuit 19 being adequate for all the quadruplex .lines terminating at a central office. In the drawing I have shown two such connecting-relays 8 in the circuit 19; but there may be a less or greater number. Furthermore, only a relatively weak current is required for the operation of even a considerablenumber of relays 8 in circuit 19, and since there is practically no sparking at the brushes of an alternating-current generator such as required for this purpose the said generator and the polar relays constitute very reliable and efficient means fol-connecting the transmitters to their lines. The armatures of these relays break contact with their contact-stops very rapidly, and therefore sparking at these contacts is practically avoided, and one difficulty heretofore experienced in the use of quadruplex systems employing currents of different direction for different transmitters is overcome. The instruments required for this system are also all of standard type, such as may be readily obtained at all times.

It Will be obvious that my invention is susceptible of many variations andmodiflcations without departing from its spirit and scope, and, further, that it is not limited to any particular type of the various instruments illustrated and that instruments of other types may be used in lieu of those illustrated. I do not limit myself, therefore, to the use of any particular type of instrument or to any particular arrangement of circuits.

hat I claim is- 1. In a telegraph system, the combination of a line conductor, two transmitters therefor and means for supplying current to said transmitters and thence to the line arranged to supply current to one transmitter of different direction from that supplied to the other, of a vibrating connector arranged to connect said transmitters to the line alternately and means for vibrating said connector comprising an electromagnet, a circuit therefor, and means for producing in said circuit a current of fluctuating character.

2. In a telegraph system, the combination of a line-conductor, two transmitters therefor and means for supplying current to said transmitters and thence to the line arranged to supply current to one transmitter of different direction from that supplied to the other, of a polar relay arranged to connect said transmitters to the line alternately, a circuit therefor, and means for producing in said circuit an alternating current.

3. In a telegraph system, the combination of a line conductor, tWo transmitters therefor and separate generators for said transmitters arranged to supply to one of said transmitters a current of different direction from that supplied to the other, of a vibrating connector arranged to connect said transmitters to the line alternately and means for vibrating said connector comprising an electromagnet, a circuit therefor, and means for producing in said circuit a current of fluctuating character.

4. In a telegraph system, the combination of a line conductor, two transmitters therefor and separate generators for said transmitters arranged to supply to one of said transmitters a current of different direction from that sup- In testimony whereof I affix my signature in the presence of two Witnesses.

JOHN o. BARCLAY.

Witnesses:

G. F. CARRINGTON, FRANK KITToN. 

